/Engine/Source/Runtime/CoreUObject/Public/UObject/UnrealType.h
Editor-only properties are those that only are used with the editor is present or cannot be removed from serialisation. Editor-only properties include: EditorOnly properties Properties that cannot be removed from serialisation are: Boolean properties (may affect GCC_BITFIELD_MAGIC computation) Native properties (native serialisation)
bool IsEditorOnlyProperty() const